POLARIZING FILTERS
Polarizers are most useful for increasing
general outdoor color saturation and contrast. Polarizers
can darken a blue sky, a key application, on color as well as on black-and-white film, but
there are several factors to remember when doing this.
To deepen a blue sky, it must be blue to start with, not white or hazy. Polarization is also angle-dependent. A blue sky will not be equally affected in all
directions. The areas of deepest blue are
determined by the following "rule of thumb."
When setting up an exterior shot, make a right angle between thumb and forefinger. Point your forefinger at the sun. The area of deepest blue will be the band outlined
by your thumb as it rotates around the pointing axis of your forefinger, directing the
thumb from horizon to horizon. Generally, as
you aim your camera either more into or away from the sun, the effect will gradually
diminish. There is no effect directly at or
away from the sun. Do not pan with a
polarizer, without checking to see that the change in camera angle doesn't create
undesirable noticeable changes in color or saturation.
Also, with an extra-wide-angle view, the area of deepest blue may appear as a
distinctly darker band in the sky. Both
situations are best avoided. In all cases,
the effect of the polarizer will be visible when viewing through it.
Polarizers need approximately 1-1/2 to 2 stops
exposure compensation, usually without regard to rotational orientation or subject matter. They are also available in combination with
certain standard conversion filters, such as the 85BPOL.
In this case, add the polarizer's compensation to that of the second filter.
Certain camera optical systems employ internal
surfaces that themselves polarize light. Using
a standard (linear) polarizer will cause the light to be further absorbed by the internal
optics, depending on the relative orientation. A
Circular Polarizer is a linear one to which
has been added,on the side facing the camera, a quarter wave "retarder." This "corkscrews" the plane of
polarization, effectively depolarizing it, eliminating the problem. The Circular Polarizer otherwise functions in the
same manner.
Combine the Tiffen ENHANCING filter with a
Polarizer filter for more dramatic effects.
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Tiffen Filter Prices
